Electric stopping device for stretching machines



Dec. 18, 1928. 1,696,109

w. DEWHURST ELECTRIC STOPPING DEVICE FOR STRHTCHING MACHINES Filed July 5, 1928 A TTORNEY.

Patented Dec. 13, 1928.

UNITED STATES -WILLIAM DEWHURST, OF METHUEN, MASSACHUSETTS.

I ELECTRIC STOPPING DEVICE FOR STRETCHING MACHINES.

Application filed July 5,

This invention is a stop motion of the elec tric type for such cloth handling machines as are known as tent-ering machines, or it may be used in connection with certain types of meroerizing machines or other machines for stretching cloth laterally.

Such machines are generally from 90 to 100 ft. in length and the cloth iscarried along through a series of steam heatedvpipes in a chamber by endless chains of clips or pincers which move along and then around and back to the point of beginning. The clips or pincers are so arranged that their jaws automatically seize the edges of the cloth at the receiving end of the machine and as they move along, move away from each other so as to stretch it while passing between the hot ipes. After they have traversed the main length of the machine, the pincer jaws are automatically caused to open when they move around a wheel or pulley at the delivery end, releasing the cloth at a given point, which point is where they begin to move away from the general line of motion. 7

Occasionally, because of a flaw in the cloth or because the clips or pincers do not let go at the right time, a piece of cloth is torn out and carried along around a delivery pulley causing very serious damage to the machinery.

When a substantial piece of cloth is so carried into the pipe chamber, it is a hot, dangerous, and disagreeable job to extricate it and causes a delay of 45 minutes to an hour or more with the consequent loss of production.

This device is an electricswitchpositioned ina switch circuit and having a handleor arm in such positionclose to the pincers but not touching them so that ii' a bunch of cloth is carried around, such-bunch will strike the handle and throw the switch which preterably breaks, although it maybe designedto make, the switch circuit whereby a suitable electro-magnetwill operate a stopping lever to stop the whole machine.

Preferably I use an electric driving circuit of the three phase or one phase type and interpose in this circuit as a stopping and starting lever for the machine, a switch which has its operating or movable member controlled by such electro-magnet.

This magnet however might operate a shipping lever for shifting a belt, clutch or other similar device to stop the nrnichineu 1928. Serial no. 290,675.

In the drawings, Fig. 1 is a diagrammatic plan view of the device applied to a tentering machine driven by ing circuit. v

Fig. 2 is an elevation of oneof my pre ferred form of automatic stopping switches.-

as viewed from the point X in Fig, 1.

Fig. 3 is an elevation as t'romthe left of Fig. I 4 v Fig. 4 is a sectional detail of thegvarious switches, shown diagrammatically applied to a single phase driving circuit.

Fig. 5 is a view similar to Fig. 2 of a modiiied form of switch.

Fig. 6 is a view partly in section from the left of Fig. 5.

In the drawings, A and B represent the cloth carrying or stretching mechanism be-' tween which the cloth C passes.

A and B are each made up of endless chains of clips or pincers, those shown in the drawings including a topjaw 20 and a bottom jaw 21. v

These endless chains are caused to travel respectively around the pulleys 10 and 11 for A and 12 and 13 for B. I

By means of suitable devices which are old, the pincers are caused to seize the edges of the cloth at 23 and 24 and to hold-it firmly as it travels along at 14 and 15 until it reaches the points at approximately 25 and 26 where by means of suitable plow or release mechanism '27 or 28 they are supposed to let go allowing the cloth to continue asat 29 and to be rolled up or handled bysuitable other mechanism. p

- Where, as shown at 40, a strip of the cloth is ripped off, and either is not released by the pincers or gets tangled upwith them so that it is carried'along as'around one of the delivery pulleys 10 or 1.2, serious delay and damage results. In such machines as now constructed, there are usually two or more stopping devices whereby the machine can be stopped by hand in case of accident and to avoid trouble.

Where an electric motor such as R is used for the main drive, there is interposed in the circuits therefor, which are indicated by Y,

15 i and 156, :a controller 0 by which the speed of the motor is controlled and by which the circuit can be opened andthe motor stopped.

a three phase A. C. drivinterpose a switch M between and 156 which ordinarily is kept closed by the electromagnet 53 interposed in the switch circuit indicated by P.

The moving members 55 of switch M are pivoted at 5 1, 54, 5-1 as shown in Fig. '1 and when closed by magnet 53 close the circuit through contacts 56 and wires 156. This is the normal operating position of the parts while the machine is running, the switch being of the circuit breaker type.

In Fi 4, the parts are the same except that thereis only one movable switch member and the switch circuit is not a three phase one.

lVhen the switch circuit P is broken as by means of the, hand operable push button switch F at the other end of the machine or by the operation-of my automatic switch indicated by G, the spring 155 opens the main circuit, stops the motor R and therefore the machine.

This switch circuit obtains current asfrom a battery 57 from which extend the wires 59 and 58. Wire 59 passes around magnet 53 and thence through wire 50 to a hand push button switch indicated by F located at the other or receiving end of the machine. This switch enablesdthe operator who may beat that end to open or close the switch circuit P thus stopping the mach ne from the other end. This switch'F preferably is of thepush button type which canbe opened or closed and will stay in the desired position as by means of pin 167 which can be pushed down through hole 166 and turned under cover 68, oriturned and released through hole 166.

The conductor 51 from F enters one end and the conductor 58 from battery 57 enters the other end of the automatic switch G.

The contact parts of automatic electric switch G andhand switch F aresubstantially the same as each includes a. box such as 69 In ving a. cover 68, there being openings through which pass the insulated contact wires such as 50,151 to the contacts 161 and 163 insulated from the box by insulation 162 and'164.

61 is a hollow guidopost which sticks=up from the bottom of box 69 and-serves as aguide for the capped cylindrical push button preferably of insulating material and which carries the contact disk 160. hen 60 and 160 are pushed down as shown in the full lines, the current passes through 160 -from the contacts 161 and 163 in each case the circuit being to that extent closed but when released, the action of spring 165 moves both upto the dotted linepositions shown in Figs. 3 and 4 and the circuit is opened.

Switch Fisnormally closed and locked in place by a pin 167 and switch G is normally also closed and lockedin position by means of the rocking arm 63 pivoted to an arm 264 attached to box 69 and having atone end 65 an adjustable thumbnut which engages the top of'contact 60, its other end 66 resting or dinarily on the top end 70 of a. trigger arm which is pivoted to the frame at 71. This trigger arm extends downward at 72 in the form of a tail or operating handle which is insuch position that it will he struck by any bunch oiiclothsuclras -lOawhich may become caught in the traveling clips or pincers and get by the-releasing devices 27 and 28.

The conductorlil enters a plate 87 oi insula-ting material at 86 which has a contact.m-

sort 89 in a position to be engaged by spring pressed finger carried by switch arm 80 pivoted at 81 and connected .with the conduc tor 58 its other end orhandlc SQbeinglin the same position as the tail or operating han (He-72. I

When this tail 82 is struck by a piece of cloth such as 40 and moved to the dotted line position,-the switch circuitP is broken and the machine is stopped.

Preferably there are two of the automatic stopping switches such as G and G or R, each one just beyond'the clip releasing devices 28 and 27, and one or more hand stopping switches such as F, all in a switch circuit which is normally kept closed.

It is obvious that arm 55 might be, or might be replaced by, a shipper handle or by any other drive mechanism stopping device.

I claim: I

1. In a cloth stretching machine of a. type wherein the cloth is carried along between endless chains of pinccrs, whichpincors move around. and away from the point where they normally release the cloth; the combination of two automatic electric stopping switches each positioned beyond said releasing point and each having a handle so pivoted that it will be struck and thrown by any substantial piece of cloth which is carried away and around .from said releasing point; a hand operable switch positioned at a third point on said machine; the automatic switches and said handswitch being interposed in a switch circuit from a source of electricpower, said circuit also passing through an electroanagnot which has an armature the operating member of adevice for stopping and starting the cloth handling'nnichine, the parts being so arranged that the machine is stopped when the switch circuit is open.

2(In a cloth stretchingmachine of the type wherein the cloth is carried along between endless ohains of pincers, which pinsource of electric power, said circuit also passing through an electrically operative stop- 10' ping device, such switch, source of electric power and stopping device being so arranged that the machine is stopped when the circuit is open.

WILLIAM DEWHURST. 

